Machine for grinding and polishing plate-glass.



Patented Dec. I9, I899.

M. R. WELTY.

MACHINE FDR GRINDING AND POLISHING PLATE GLASS.

(Application filed Sept. 1, 1899.3

(N0 Mudelf) 2 Sheets-Sheet l.

I j l o 7 29 g L 70 g 70 77 20 r i 77 7o I l! i 7 7' z 7 No. 639,323. Patented Dec. l9, I899.

M. n. WELTY.

MACHINE FOR GRINDING AND POLISHING PLATE GLASS.

(Application filed Sept. 1, 1899.)

(No Model.) I Sheets-Sheet 2.

n. IIIIIIII" .nmHIH HIIIIIWv Q vihmaoea MCZSOILA Q my 11 i I abtomwgyg UNTTE STATES PATENT FFICE.

MASON R. VVELTY, OF HUNKERS, PENNSYLVANIA.

MACHINE FOR GRINDING AND POLISHING PLATE-GLASS.

SPECIFICATION forming part of Letters Patent N 0. 639,323, dated December 19, 1899. Application filed September 1, 1899. Serial No. 729,201. (No model.)

To all whom it may concern.-

Be it known that I, MASON R. WELTY, a citizen of the United States, residing at H unkers, in the county of Westmoreland and State of Pennsylvania, haveinvented certain new and useful Improvements in Machines for Grinding and Polishing Plate-Glass; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention has for its objectto devise a machine for grinding plate-glass evenly and smoothly and to obviate the formation of rings and hollow grinding, which are objectionable features commonly met with in the operation of machines as generally constructed.

A further purpose of the invention is to facilitate access 'to the active or abrading surfaces of the grinding-wheels for repairs and to enable a substitution of rubbers, the grinding-wheels being advanced automatic,- ally as the work of grinding progresses.

A still further purpose of the invention is to combine with the grinding-wheels means for imparting an oscillating motion thereto, said means being automatic in operation.

Various other advantages will suggest them selves as the nature and details of the invention are comprehended; and to this end and to a full knowledge of the structural features reference is to be had to the following description and drawings hereto attached, in which- Figure 1 is a front View of a machine constructed in accordance with and embodying the essential features of the invention. Fig. 2 is a top plan View. Fig. 3 is a central longitudinal section. Fig. 4 is a sectional detail of the means and mountings for the outer end of the shaft-gearing and grinding-wheel.

Corresponding and likeparts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

The framework for supporting the operating parts may be of any desired formation, the several beams being connected together in any substantial manner. The framework represented by the numeral 1 may be of a portable character or may be the interior structure of a building, according to the location and manner of mounting the operating parts. The counter-shaft 2, which is driven from a suitable source of power, is provided with pulleys 3 and 4.,and shafts 5 in longitudinal alinement are provided with pulleys 6, which are connected by belts 7 and 8 with the respective pulleys 3 and 4, the belt 7 being cross and the belt 8 open, whereby the shafts 5 are driven in reverse directions. Grinding-wheels 9 are secured to the inner or opposing ends of the shafts 5 and are rotated in opposite directions.

Each of the shafts 5 is mounted in the lower ends of hangers 10, suspended coaxially with the counter-shaft 2 and preferably mounted thereon for swinging movement. The hangers 10 are spaced apart and are connected by means of abrace 11 of approximately X form. The end portions of the brace 11 are bolted or otherwise secured to the upper and lower ends, respectively, of corresponding hangers 10, whereby said hangers move in unison and, with the brace, constitute a swinging frame, which supports the grinding mechanism. Oscillatory movement is imparted to the swinging frames in an automatic and positive -manner and in reverse directions, so that when one of the shafts 5 moves forward the other moves rearward, which is of material advantage in equalizing the strain and effect* ing the best results.

In order to impart a reverse oscillatory movement to the swinging frames, the shaft 12 is provided and is formed with oppositelydisposed crank portions 13, which are connected by links 14 with the respective shafts 5. The shaft 12 is driven from any moving part of the machine and for convenience is provided with a band-pulley 15, which is connected by a drive-belt with a corresponding pulley 16 on the counter-shaft 2. The pulley 15 is of larger diameter compared with the pulley 16, whereby the shaft 12 is rotated at a low speed, which is desirable, so as not to oscillate the swinging frames too rapidly.

A bracket 17 is secured to the lower end of the extreme hangers 10 of the swinging frames, and its lower end is formed with a threaded opening in line with the shaft 5 and is adapted to receive a set-screw 18, whose inner end portion enters an opening in the outer end of the adjacent shaft 5, A collar or stop 19 is provided at the outer end of the set-screw and is adapted to engage with the inner side of the outer cross-bar of a slidablymounted frame 20, the inner end of the hub of the hand-wheel of the set-screw engaging with the outer side of said cross-bar, whereby a movement of the set-screw in either direction effects a corresponding movement of the frame 20. end portion of each shaft 5 and is adapted to engage with the inner side of the inner end of the cross-bar of the frame 20 and receives the end thrust of a spring 22 of the coil type interposed between said collar 21 and the bracket 17. inner end portion of the set-screw and the outer end portion of the shaft 5 and normally exerts a pressure to move the shaft 5 inward and force the grinding-wheel against the side of the plate-glass in position to be ground or polished. The slidable frame 20 is of rectangular and oblong form, and its outer crossbar is apertured to admit of the set-screw 18 passing therethrough, and its inner cross-bar is correspondingly apertured to receive the outer end portion of the shaft 5, which is adapted to rotate freely therein. Whenitis required to move the grinding-wheel outward forany purpose, such as to admit of the plate-glass being placed in position for operation or removed after being polished or to admit of the buffers being properly adjusted or substituted, it is only necessary to rotate the set-screw to effect an outward movement thereof, when its collar 19, bearing against the outer cross-bar of the frame, will cause the latter to move outward and draw the shaft 5 outward by reason of the inner cross-bar of the frame engaging with the collar 21. When the plate-glass is in position, the set-screw is moved inward, thereby permitting the spring 22 to react and move the shaft 5 inward and the plate to be ground and polished.

The plateglass holder is located in the space formed between the opposing surfaces of the grinding-wheels, and consists of a lower bar 23,an upper bar 2et,and vertical clamp-bars 26, parallel with the clamp-bars 25 and set in therefrom a short distance. The plate-glass to be operated upon is held between the bars 23, 24, and 26 and is simultaneously ground and polished upon both sides by means of the grinding-wheels, the latter receiving a combined rotary and oscillatory movement,

the latter movement obviating the formation of rings and hollow grinding of the glass and insuring flat surfaces.

The swinging frames are mounted upon the counter-shaft, thereby resultingin simplicity and compactness of arrangement and preventing any variation between the axis of the counter-shaft and the shafts 5 in the various stages of movement of said shafts 5 due to the oscillation of the swinging frames. The mounting of the operating parts so as to effect a reverse movement of the grinding- A collar 21 is applied to the outer This spring 22 surrounds the.

wheels both as regards rotary and reciprocating movements results in a neutralization of the forces upon opposite sides of the plate, whereby it is not necessary to make the holder for the glass exceedingly heavy and to provide a firm carriage in order to prevent creeping or movement of the glass from between the grinding-wheels when the machine is in operation, as would be the case if the grinding-wheels rotated in the same direction and oscillated in the same direction. The abrading material, such as sand and water, is fed to the grinding-wheels and plate from a hopper 27, located .above the grinding mechanism and having its bottom perforated at intervals for the escape of the sand and wrter.

Within the spirit of the invention the grinding-wheels may have any form and the working parts may be mounted in any substantial manner. Hence it is to be understood that in constructing and installing an apparatus constructed in accordance with this invention various changes in the form, proportion, and minor details of construction maybe resorted to without departing from the spirit of the invention.

Having thus described the invention, what is claimed as new is- 1. In apparatus for grinding and polishing plate-glass, a pair of grinding-wheels located for simultaneous action upon opposite sides of the plate-glass placed between them, and means for imparting a simultaneous oscillatory movement to the grinding-wheels, as and for the purpose set forth.

2. In apparatus for grinding and polishing plate-glass, a pair of grinding-wheels arranged for simultaneous action upon opposite sides of the plate-glass placed between them, and mechanism for simultaneously oscillatingthe grinding-wheels in reverse directions, as and for the purpose set forth. force the grinding-wheel against the side of 3. In apparatus for grinding and polishing plate-glass, a counter-shaft, longitudinallyalined shafts provided at their inner ends with grinding-Wheels, hangers carrying the said shafts and mounted coaxially with the counter-shaft, means for imparting movement to the'grinding-wheels from the counter-shaft in reverse directions, and means for imparting an oscillatory movement to the hangers, as and for the purpose set forth.

4. In apparatus for grinding and polishing plate-glass, a counter-shaft, hangers mounted coaxially with the counter-shaft, grinding wheels, shafts mounted in the free ends of the hangers and having the grinding-wheels applied thereto, means for driving said shafts in reverse directions from the counter-shaft, and a shaft provided with oppositely-extending crank portions having connection with the grinding-wheel shafts, the parts being combined and arranged for operation in the manner and for the purpose specified.

5. In apparatus for grinding and polishing plate-glass, a shaft mounted for rotary and sliding movements and bearing a grinding- Wheel, a set-screw having itsinner end portion operatively connected With the adjacent terminal portion of the shaft, a spring disposed to normally move the shaft to cause the grinding-Wheel to bear against the surface to be operated upon, and a connection between the set-screw and shaft for moving the latter outward against the tension of the aforesaid spring, substantially as set forth.

6. In apparatus for grinding and polishing plate-glass, a shaft mounted for rotary and sliding movements and bearingagrinding device, a set-screw, a spring normally exerting a pressure to hold the grinding device in Working relation, and a frame having loose connection with the said shaft and set-screw and adapted to move the shaft against the tension of the aforementioned spring when backing the set-screw, as and for the purpose set forth.

7. In combination, a hanger, a shaft rotatably and slidably mounted in the hanger and provided with a grinding device, a relativelyfixed bearing, a set-screw threaded in said bearing and operatively connected with the adjacent end of said shaft, collars or stops applied to the set-screw and shaft, a spring interposed between the fixed'bearing and the collar applied to the shaft, and a frame having loose connection with the set-screw and shaft and adapted to engage with the collars thereof, as and for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

MASON R. WELTY. a 8.]

WVitnesses:

GEO. S. RUMBAUGH, SARAH B. PORTZER. 

